Update System.Commandline package version

[lbussell]

ImageBuilder, file-pusher, and yaml-updater are all using System.Commandline version 2.0.0-beta1.20574.7 from 2021. A new version, 2.0.0-beta4.22272.1 is available. It has several breaking changes that are preventing it from being easily used in ImageBuilder. We may want to consider holding off on updating it until it has a stable API.

[lbussell]

[Triage] We would like to keep this package version at least relatively up-to-date.

[lbussell]

[Triage] System.Commandline is in the middle of a big re-write/re-organization: dotnet/command-line-api#2338

I don't see a lot of value in us switching to an intermediate version if we'll have to change everything again in the future. So we should wait until that is completed.